// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Author: wsfuyibing <682805@qq.com>
// Date: 2024-11-28

package message

import (
	"fmt"
	"math/rand"
	"time"
)

const (
	HashDatetime       = "060102150405" // 240506091011
	HashUndefined Hash = ""
)

// Hash
// is a type name for unique string of the message.
type Hash string

// NewHash
// creates a new hash string.
func NewHash() Hash {
	tm := time.Now()
	r1 := rand.Int31n(9999)
	r2 := rand.Int31n(9999)

	return Hash(fmt.Sprintf(`%sD%09dA%04dB%04d`,
		tm.Format(HashDatetime),
		tm.Nanosecond(),
		r1, r2,
	))
}

func (o Hash) String() string  { return string(o) }
func (o Hash) Undefined() bool { return o == HashUndefined }
